Add ArmeriaProcessor to provide ActionHook (#3732)

Motivation:

No `ActionHook` is set because `TomcarService` makes a pure `Request`. Due to this, default error handling does not work when integrating with Spring Boot.

Modifications:

- Add `ArmeriaProcessor` per `tomcat` module
- Add `ArmeriaEndpoint` to `tomcat8`
- `ArmeriaProcessor` and `ArmeriaEndpoint` are created with `MethodHandle`
- Add test

Result:

- Closes #3447

it/spring/boot2-tomcat9/src/main/java/com/linecorp/armeria/spring/tomcat/demo/ErrorHandlingController.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2021 LINE Corporation
+ *
+ * LINE Corporation licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+package com.linecorp.armeria.spring.tomcat.demo;
+
+import java.util.Map;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.google.common.collect.ImmutableMap;
+
+@RestController
+@RequestMapping("/error-handling")
+public class ErrorHandlingController {
+
+    @GetMapping("/runtime-exception")
+    public void runtimeException() {
+        throw new RuntimeException("runtime exception");
+    }
+
+    @GetMapping("/custom-exception")
+    public void customException() {
+        throw new CustomException();
+    }
+
+    @GetMapping("/exception-handler")
+    public void exceptionHandler() {
+        throw new BaseException("exception handler");
+    }
+
+    @GetMapping("/global-exception-handler")
+    public void globalExceptionHandler() {
+        throw new GlobalBaseException("global exception handler");
+    }
+
+    @ResponseStatus(code = HttpStatus.NOT_FOUND, reason = "custom not found")
+    private static class CustomException extends RuntimeException {}
+
+    private static class BaseException extends RuntimeException {
+        BaseException(String message) {
+            super(message);
+        }
+    }
+
+    @ExceptionHandler(BaseException.class)
+    public ResponseEntity<Map<String, Object>> onBaseException(Throwable t) {
+        final Map<String, Object> body = ImmutableMap.<String, Object>builder()
+                                                     .put("status", HttpStatus.INTERNAL_SERVER_ERROR.value())
+                                                     .put("message", t.getMessage())
+                                                     .build();
+        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(body);
+    }
+}

it/spring/boot2-tomcat9/src/main/java/com/linecorp/armeria/spring/tomcat/demo/GlobalBaseException.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2021 LINE Corporation
+ *
+ * LINE Corporation licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+package com.linecorp.armeria.spring.tomcat.demo;
+
+public class GlobalBaseException extends RuntimeException {
+    GlobalBaseException(String message) {
+        super(message);
+    }
+}

it/spring/boot2-tomcat9/src/main/java/com/linecorp/armeria/spring/tomcat/demo/GlobalExceptionHandler.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2021 LINE Corporation
+ *
+ * LINE Corporation licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+package com.linecorp.armeria.spring.tomcat.demo;
+
+import java.util.Map;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+import com.google.common.collect.ImmutableMap;
+
+@RestControllerAdvice
+class GlobalExceptionHandler {
+
+    @ExceptionHandler(GlobalBaseException.class)
+    public ResponseEntity<Map<String, Object>> onGlobalBaseException(Throwable t) {
+        final Map<String, Object> body = ImmutableMap.of("status", HttpStatus.INTERNAL_SERVER_ERROR.value(),
+                                                         "message", t.getMessage());
+        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(body);
+    }
+}

it/spring/boot2-tomcat9/src/main/resources/config/application.yml

@@ -2,3 +2,6 @@ armeria:
   ports:
     - port: 0
       protocol: HTTP
+server:
+  error:
+    include-message: always

it/spring/boot2-tomcat9/src/test/java/com/linecorp/armeria/spring/tomcat/demo/ErrorHandlingTest.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2021 LINE Corporation
+ *
+ * LINE Corporation licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+package com.linecorp.armeria.spring.tomcat.demo;
+
+import static net.javacrumbs.jsonunit.fluent.JsonFluentAssert.assertThatJson;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import javax.inject.Inject;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+
+import com.linecorp.armeria.spring.LocalArmeriaPort;
+
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+class ErrorHandlingTest {
+
+    private static final String TOMCAT_BASE_PATH = "/tomcat/api/rest/v1";
+
+    @LocalArmeriaPort
+    private int port;
+
+    @Inject
+    private TestRestTemplate restTemplate;
+
+    private static String tomcatBaseUrlPath(int port) {
+        return "http://localhost:" + port + TOMCAT_BASE_PATH;
+    }
+
+    @ParameterizedTest
+    @CsvSource({
+            "/error-handling/runtime-exception, 500, runtime exception",
+            "/error-handling/custom-exception, 404, custom not found",
+            "/error-handling/exception-handler, 500, exception handler",
+            "/error-handling/global-exception-handler, 500, global exception handler"
+    })
+    void shouldReturnFormattedMessage(String path, int status, String message) throws Exception {
+        final ResponseEntity<String> response =
+                restTemplate.getForEntity(tomcatBaseUrlPath(port) + path, String.class);
+        assertThat(response.getStatusCode()).isEqualTo(HttpStatus.valueOf(status));
+        assertThatJson(response.getBody()).node("status").isEqualTo(status);
+        assertThatJson(response.getBody()).node("message").isEqualTo(message);
+    }
+}

it/spring/boot2-tomcat9/src/test/java/com/linecorp/armeria/spring/tomcat/demo/SpringTomcatApplicationItTest.java

@@ -20,9 +20,8 @@
 
 import javax.inject.Inject;
 
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
@@ -32,15 +31,13 @@
 import org.springframework.boot.web.server.WebServer;
 import org.springframework.context.ApplicationContext;
 import org.springframework.http.HttpStatus;
-import org.springframework.test.context.junit4.SpringRunner;
 
 import com.linecorp.armeria.internal.server.tomcat.TomcatVersion;
 import com.linecorp.armeria.server.Server;
 import com.linecorp.armeria.server.ServerPort;
 
-@RunWith(SpringRunner.class)
 @SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
-public class SpringTomcatApplicationItTest {
+class SpringTomcatApplicationItTest {
     @Inject
     private ApplicationContext applicationContext;
     @Inject
@@ -55,7 +52,7 @@ public class SpringTomcatApplicationItTest {
     @Value("${armeria-tomcat.version.minor:0}")
     private int tomcatMinorVersion;
 
-    @Before
+    @BeforeEach
     public void init() throws Exception {
         httpPort = server.activePorts()
                          .values()
@@ -68,18 +65,18 @@ public void init() throws Exception {
     }
 
     @Test
-    public void contextLoads() {
+    void contextLoads() {
         assertThat(greetingController).isNotNull();
     }
 
     @Test
-    public void verifyTomcatVersion() {
+    void verifyTomcatVersion() {
         assertThat(TomcatVersion.major()).isEqualTo(tomcatMajorVersion);
         assertThat(TomcatVersion.minor()).isEqualTo(tomcatMinorVersion);
     }
 
     @Test
-    public void verifySingleConnector() {
+    void verifySingleConnector() {
         // Relevant to Tomcat 9.0
         assertThat(applicationContext).isInstanceOf(WebServerApplicationContext.class);
         final WebServer webServer = ((WebServerApplicationContext) applicationContext).getWebServer();
@@ -91,7 +88,7 @@ public void verifySingleConnector() {
     }
 
     @Test
-    public void greetingShouldReturnDefaultMessage() throws Exception {
+    void greetingShouldReturnDefaultMessage() throws Exception {
         assertThat(restTemplate.getForObject("http://localhost:" +
                                              httpPort +
                                              "/tomcat/api/rest/v1/greeting",
@@ -100,7 +97,7 @@ public void greetingShouldReturnDefaultMessage() throws Exception {
     }
 
     @Test
-    public void greetingShouldReturnUsersMessage() throws Exception {
+    void greetingShouldReturnUsersMessage() throws Exception {
         assertThat(restTemplate.getForObject("http://localhost:" +
                                              httpPort +
                                              "/tomcat/api/rest/v1/greeting?name=Armeria",
@@ -109,7 +106,7 @@ public void greetingShouldReturnUsersMessage() throws Exception {
     }
 
     @Test
-    public void greetingShouldReturn404() throws Exception {
+    void greetingShouldReturn404() throws Exception {
         assertThat(restTemplate.getForEntity("http://localhost:" +
                                              httpPort +
                                              "/tomcat/api/rest/v1/greet",

tomcat8/build.gradle

@@ -24,13 +24,18 @@ dependencies {
 // NB: We should never add these directories using the 'sourceSets' directive because that will make
 //     them added to more than one project and having a source directory with more than one output directory
 //     will confuse IDEs such as IntelliJ IDEA.
-tasks.compileJava.source "${rootProject.projectDir}/tomcat9/src/main/java"
-tasks.compileJava.exclude '**/ConfigFileLoaderInitializer*'
-tasks.processResources.from "${rootProject.projectDir}/tomcat9/src/main/resources"
-tasks.compileTestJava.source "${rootProject.projectDir}/tomcat9/src/test/java"
-tasks.processTestResources.from "${rootProject.projectDir}/tomcat9/src/test/resources"
-tasks.sourcesJar.from "${rootProject.projectDir}/tomcat9/src/main/java"
-tasks.sourcesJar.from "${rootProject.projectDir}/tomcat9/src/main/resources"
-tasks.sourcesJar.exclude '**/ConfigFileLoaderInitializer*'
-tasks.javadoc.source "${rootProject.projectDir}/tomcat9/src/main/java"
-tasks.javadoc.exclude '**/ConfigFileLoaderInitializer*'
+def tomcat9ProjectDir = "${rootProject.projectDir}/tomcat9"
+// Copy common files from tomcat9 module to gen-src directory in order to use them as a source set.
+task generateSources(type: Copy) {
+    from "${tomcat9ProjectDir}/src/main/java"
+    into "${project.ext.genSrcDir}/main/java"
+    exclude '**/ArmeriaProcessor*'
+    exclude '**/ConfigFileLoaderInitializer*'
+    exclude '**/package-info.java'
+}
+
+tasks.compileJava.dependsOn(generateSources)
+tasks.compileTestJava.source "${tomcat9ProjectDir}/src/test/java"
+tasks.processResources.from "${tomcat9ProjectDir}/src/main/resources"
+tasks.processTestResources.from "${tomcat9ProjectDir}/src/test/resources"
+tasks.sourcesJar.from "${tomcat9ProjectDir}/src/main/resources"